Collagen is a major structural protein in the matrix of animal cells and the most widely distributed and abundant functional protein in mammals. Collagen’s good biocompatibility, biodegradability and biological activity make it a very valuable biomaterial. According to the source of collagen, it can be broadly categorized into two types: one is animal collagen; the other is recombinant collagen. Animal collagen is mainly extracted and purified from animal connective tissues by chemical methods, such as acid, alkali and enzyme methods, etc. Recombinant collagen refers to collagen produced by gene splicing technology, where the amino acid sequence is first designed and improved according to one’s own needs, and the gene sequence of improved recombinant collagen is highly consistent with that of human beings, and then the designed gene sequence is cloned into the appropriate vector, and then transferred to the appropriate expression vector. The designed gene sequence is cloned into a suitable vector, and then transferred to a suitable expression system for full expression, and finally the target protein is obtained by extraction and purification technology. Recombinant collagen has excellent histocompatibility and water solubility, can be directly absorbed by the human body and participate in the construction of collagen, remodeling of the extracellular matrix, cell growth, wound healing and site filling, etc., which has demonstrated significant effects, and has become the focus of the development of modern biomedical materials. This paper firstly elaborates the structure, type, and tissue distribution of human collagen, as well as the associated genetic diseases of different types of collagen, then introduces the specific process of producing animal source collagen and recombinant collagen, explains the advantages of recombinant collagen production method, and then introduces the various systems of expressing recombinant collagen, as well as their advantages and disadvantages, and finally briefly introduces the application of animal collagen, focusing on the use of animal collagen in the development of biopharmaceutical materials. In terms of application, it focuses on the use of animal disease models exploring the application effects of recombinant collagen in wound hemostasis, wound repair, corneal therapy, female pelvic floor dysfunction (FPFD), vaginal atrophy (VA) and vaginal dryness, thin endometritis (TE), chronic endometritis (CE), bone tissue regeneration in vivo, cardiovascular diseases, breast cancer (BC) and anti-aging. The mechanism of action of recombinant collagen in the treatment of FPFD and CE was introduced, and the clinical application and curative effect of recombinant collagen in skin burn, skin wound, dermatitis, acne and menopausal urogenital syndrome (GSM) were summarized. From the exploratory studies and clinical applications, it is evident that recombinant collagen has demonstrated surprising effects in the treatment of all types of diseases, such as reducing inflammation, promoting cell proliferation, migration and adhesion, increasing collagen deposition, and remodeling the extracellular matrix. At the end of the review, the challenges faced by recombinant collagen are summarized: to develop new recombinant collagen types and dosage forms, to explore the mechanism of action of recombinant collagen, and to provide an outlook for the future development and application of recombinant collagen.

ObjectiveTo investigate the mechanism by which Feixin decoction treats hypoxic pulmonary hypertension （HPH） by regulating the peroxisome proliferator-activated receptor gamma （PPARγ）/nuclear factor-kappa B （NF-κB）/NOD-like receptor pyrin domain containing 3 （NLRP3） signaling pathway. MethodsForty-eight male SD rats were randomly allocated into normal， hypoxia， and low-， medium- and high-dose （5.85， 11.7， 23.4 g·kg^-1， respectively） Feixin decoction groups， with 8 rats in each group. Except the normal group， the remaining five groups were placed in a hypoxia chamber with an oxygen concentration of （10.0±0.5）% for 8 h per day， 28 days， and administrated with corresponding drugs during the modeling process. After 4 weeks of treatment， echocardiographic parameters ［pulmonary artery acceleration time （PAT）， pulmonary artery ejection time （PET）， right ventricular anterior wall thickness （RVAWd）， and tricuspid annular plane systolic excursion （TAPSE）］ were measured for each group. The right ventricular systolic pressure （RVSP） was measured by the right heart catheterization method， and the right ventricular hypertrophy index （RVHI） was calculated by weighing the heart. The pathological changes in pulmonary arterioles were observed by hematoxylin-eosin staining. The co-localization of α-smooth muscle actin （α-SMA） with NLRP3， N-terminal gasdermin D （N-GSDMD）， and cysteinyl aspartate-specific proteinase-1 （Caspase-1） in pulmonary arteries was detected by immunofluorescence. The protein levels of PPARγ， NF-κB， NLRP3， apoptosis-associated speck-like protein containing a CARD （ASC）， N-GSDMD， interleukin-1β （IL-1β）， interleukin-18（IL-18）， and cleaved Caspase-1 in the lung tissue was determined by Western blot. The ultrastructural changes in pulmonary artery smooth muscle cells （PASMCs） were observed by transmission electron microscopy. ResultsCompared with the normal group， the hypoxia group showed increased RVSP and RVHI （P<0.01）， decreased right heart function （P<0.01）， increased pulmonary vascular remodeling （P<0.01）， increased co-localization of α-SMA with NLRP3， N-GSDMD， and Caspase-1 in pulmonary arterioles （P<0.01）， up-regulated protein levels of NF-κB， NLRP3， ASC， N-GSDMD， IL-1β， IL-18， and cleaved Caspase-1 in the lung tissue （P<0.05， P<0.01）， a down-regulated protein level of PPARγ （P<0.05， P<0.01）， and pyroptosis in PASMCs. Compared with the hypoxia group， Feixin decoction reduced RVSP and RVHI， improved the right heart function and ameliorated pulmonary vascular remodeling （P<0.05， P<0.01）， decreased the co-localization of α-SMA with NLRP3， N-GSDMD， and Caspase-1 （P<0.05， P<0.01）， down-regulated the protein levels of NF-κB， NLRP3， ASC， N-GSDMD， IL-1β， IL-18， and cleaved Caspase-1 in the lung tissue （P<0.05， P<0.01）， up-regulated the protein level of PPARγ （P<0.05， P<0.01）， and alleviated pyroptosis in PASMCs. ConclusionFeixin decoction can ameliorate pulmonary vascular remodeling and right heart dysfunction in chronically induced HPH rats by regulating pyroptosis in PASMCs through the PPARγ/NF-κB/NLRP3 pathway.

In this study,the immunological characteristics of the PhoP protein were explored with a two-component system of Mycobacterium tuberculosis(Mtb).Bioinformatics was used to predict the B and T cell epitopes of the PhoP protein.A re-combinant expression plasmid was constructed by PCR analysis of the phoP sequence and cloning into the prokaryotic expres-sion vector pET-28a(+).Competent Escherichia coli BL21 cells were transformed with the recombinant plasmid and expres-sion was induced with IPTG.The recombinant PhoP protein was purified by affinity chromatography.Serum levels of PhoP-specific antibodies in Mtb-infected mice and tuberculosis(TB)patients were analyzed with an ELISA.BALB/c mice were im-munized with the PhoP recombinant protein by intramuscular injection.Sera of mice were collected and antibody titers were detected with an ELISA and specificity was assessed by West-ern blot analysis.Mouse splenocytes were isolated and the pro-portions of IFN-y-positive cells and cytokine levels were detec-ted with an ELISpot and ELISA,respectively.Bioinformatics i-dentified 24 B cell and 11 T cell epitopes of the PhoP protein.A prokaryotic recombinant vector of PhoP was successfully con-structed and the recombinant PhoP protein was obtained by purification.Specific antibody levels to PhoP in sera of Mtb in-fected mice and TB patients increased significantly,with preci-sion of 99.9％and 82.5％,and specificity of 100％,respectively.PhoP protein immunization successfully induced production of specific antibodies in mice.Stimulated by antigens in vitro,IL-2 and IFN-γ levels were significantly increased in the splenocytes of immunized mice.Immunization with the PhoP protein induce a humoral immune response and Thl-dominated cellular immu-nity,indicating that the PhoP protein was immunogenic with diagnostic efficacy for TB.These results lay a foundation to clari-fy the role of PhoP in Mtb infection and application for diagnosis and prevention of TB.

A prokaryotic expression vector for the mutant diphtheria toxin CRM197 was constructed and expressed in Esch-erichia coli cells.Anti-CRM197 antibody concentrations were detected in serum samples of healthy volunteers.The crm 197 gene was codon-optimized in E.coli and cloned into the plasmid pET28a(+)under optimized expression conditions.CRM197 was purified using Ni-NTA spin columns and ion exchange chromatography,and confirmed by western blot analysis.The puri-fied CRM197 was used to detect specific anti-CRM197 antibody levels in serum samples of different age groups.The results showed that soluble codon-optimized CRM197 was successfully expressed under optimized expression conditions.The purity of CRM197 was more than 95％,as determined with Ni-NTA spin columns and ion exchange chromatography,consistent with the single specific bands obtained by western blot analysis and detection of serum levels of the anti-CRM197 antibody.Collec-tively,these results confirmed that the proposed expression strategy achieved high-yield production of soluble CRM197,al-though high levels in human serum may affect evaluation of immune interactions with glycan-CRM197 conjugates for applica-tion as a diagnostic antigen.The diphtheria mutant toxin CRM197 is used in many conjugate vaccines.The synthetic crm 197 gene with codon optimization in pET28a was transformed into E.coli Origami B(DE3)cells.CRM197 was induced by isopro-pyl β-d-1-thiogalactopyranoside and high level accumulation of soluble CRM197 was purified using Ni-NTA spin columns and ion exchange chromatography.The purity of the final prepara-tion reached 95％.CRM197 was used to detect the concentra-tions of the anti-CRM197 antibody in serum samples of healthy volunteers of different ages.The proposed expression strategy yielded high production of CRM197,which could interfere with evaluations of induced immune interactions by glycan-CRM197 conjugates and prohibit application as a diagnostic antigen.

Objective:To explore the changes of serum levels of angiopoictin-1(Angpt1)and endothelin-1(ET-1)in patients with newly-onset atrial fibrillation(AF)after heart valve replacement,and analyze their clinical sig-nificance.Methods:A total of 130 patients who underwent heart valve replacement in our hospital from January 2020 to March 2022 were divided into no AF group(n=72)and AF group(n=58)according to presence of AF within 7d after surgery.Serum levels of Angpt1 and ET-1 were detected by ELISA in two groups;the correlation between serum Angptl and ET-1 was analyzed by Pearson method in AF patients;ROC curve analysis was used to analyze the predictive value of serum Angpt1 and ET-1 levels for postoperative AF in these patients;Logistic re-gression was used to analyze the influencing factors of postoperative AF in these patients.Results:The left atrial diameter(LAD),proportion of NYHA class Ⅳ and cardiopulmonary bypass time in AF group were significantly higher than those of no AF group(P＜0.05 or＜0.01).One day after surgery,compared with no AF group,serum Angpt1 level significantly reduced and ET-1 level significantly increased in AF group(P＜0.001 both).Pearson correlation analysis indicated that serum Angpt1 level was significant inversely correlated with ET-1 level in AF pa-tients(r=-0.366,P=0.005).ROC analysis indicated that area under the curve(AUC)of combined detection of serum Angpt1 and ET-1 in predicting AF after heart valve replacement was significantly higher than those of each single detection(Z=2.761,1.998,P=0.006,0.046).Multivariate Logistic regression analysis indicated that LAD,NYHA class Ⅳ,cardiopulmonary bypass time and postoperative ET-1 were independent risk factors for postoperative AF in these patients(OR=1.471～1.739,P＜0.05 or＜0.01),while postoperative Angpt1 was its independent protective factor(OR=0.634,P=0.004).Conclusion:Serum Angpt1 level significantly reduces and ET-1 level significantly increases in patients with newly-onset AF after heart valve replacement.Combined detec-tion of Angpt1 and ET-1 levels possesses high predictive value for postoperative AF.

Patients with severe trauma require an extremely timely treatment and transfusion plays an irreplaceable role in the emergency treatment of such patients. An increasing number of evidence-based medicinal evidences and clinical practices suggest that patients with severe traumatic bleeding benefit from early transfusion of low-titer group O whole blood or hemostatic resuscitation with red blood cells, plasma and platelet of a balanced ratio. However, the current domestic mode of blood supply cannot fully meet the requirements of timely and effective blood transfusion for emergency treatment of patients with severe trauma in clinical practice. In order to solve the key problems in blood supply and blood transfusion strategies for emergency treatment of severe trauma, Branch of Clinical Transfusion Medicine of Chinese Medical Association, Group for Trauma Emergency Care and Multiple Injuries of Trauma Branch of Chinese Medical Association, Young Scholar Group of Disaster Medicine Branch of Chinese Medical Association organized domestic experts of blood transfusion medicine and trauma treatment to jointly formulate Chinese expert consensus on blood support mode and blood transfusion strategies for emergency treatment of severe trauma patients ( version 2024). Based on the evidence-based medical evidence and Delphi method of expert consultation and voting, 10 recommendations were put forward from two aspects of blood support mode and transfusion strategies, aiming to provide a reference for transfusion resuscitation in the emergency treatment of severe trauma and further improve the success rate of treatment of patients with severe trauma.

Objective To comprehensively excavate and analyze the research status,research hotspots and future trends of the literature related to the field of acupoint catgut embedding therapy for pain treatment in the CNKI database.Methods We searched the CNKI database from its establishment to June 2022,and scientifically analyzed the authors,keywords,and institutions of the included literature of acupoint catgut embedding therapy for pain treatment through specific algorithms of Citespace to generate a visual knowledge map.Results A total of 319 documents were included for statistical analysis,the number of publications in the field of acupoint catgut embedding therapy for the treatment of pain was generally on the rise,the number of publications by various authors was on the low side,and there was a lack of co-operation between the research teams,with the main institutions being the Guang'anmen Hospital,Chinese Academy of Chinese Medical Sciences,Affiliated Hospital of Youjiang Medical Universities of Nationalities and the Guangzhou University of Chinese Medicine,forming a 10-keyword clustering,and the hotspots of diseases under study were mainly mixed haemorrhoids,postoperative pain,low back and leg pain and dysmenorrhoea,etc..The main interventions were pure acupoint catgut embedding therapy and the combination of acupoint catgut embedding therapy and other acupuncture therapies,and the main research method was clinical research.Conclusion Acupoint catgut embedding therapy for the treatment of pain has a good development prospect,the future needs to deepen the clinical research,strengthen the mechanism research,pay attention to the joint use of acupoint catgut embedding therapy and other traditional Chinese medicine methods,and pay attention to the research of different thread materials.

BACKGROUND:The lower cervical vertebral pedicle is the main stress site of the posterior column of the spine,which is of great significance for the maintenance of the stability of the human center of gravity and the reduction of shock.At present,there are few reports on the characteristics of the internal bone trabeculae,and the characteristics of the joint site of the vertebral pedicle with the articular process and the vertebral body.It is urgent to understand the fine anatomical structure of the vertebral pedicle and the relationship and function of each part. OBJECTIVE:To observe the microanatomical morphology of the vertebral pedicle by Micro-CT scanning of cervical vertebra specimens,and to measure and analyze the microstructure and morphometric parameters of the bone trabecula in the cervical pedicle under normal conditions to evaluate the safety performance of the cervical spine. METHODS:Micro-CT scanning was performed on 31 sets of cervical vertebrae C3-C7.By checking and reconstructing the areas of interest in the bone trabecular within the vertebral pedicle,the morphological characteristics and distribution direction of the bone trabecular within the cervical pedicle were observed,and the bone microstructure parameters were detected,and the differences in the bone microstructure of the C3-C7 vertebral pedicle were analyzed and compared. RESULTS AND CONCLUSION:(1)The Micro-CT images showed that the honeycomb bone trabeculae of the pedicle of the lower cervical spine presented a complex network of microstructures.The trabeculae near the cortical bone were lamellar and relatively compact,extending forward toward the vertebral body and backward toward the articular process lamina.Abatoid bone trabeculae extended into the medullary cavity and transformed into a network structure,and then into rod-shaped bone trabeculae.The rod-shaped bone trabeculae were sparsely distributed in the medullary cavity.(2)Statistical results of morphological parameters of bone trabeculae showed that bone volume fraction values in C4 and C5 were higher than that in C7(P＜0.05).The bone surface/bone volume value in C7 was higher than that in C3,C4 and C6(P＜0.05).The bone surface density of bone trabeculae in C7 was higher than that in C3,C4,C5 and C6(P＜0.05).Trabecular thickness in C7 was higher than that in C3,C4 and C5(P＜0.05).Bone surface/bone volume and bone surface density of the left pedicle bone trabecular were greater than those on the right side(P＜0.05).(3)The microstructural changes of C3-C7 were summarized,in which the load capacity and stress of the C7 pedicle were poor,and the risk of injury was high in this area.

Objective:To explore the correlation between the ratio of C-reactive protein (CRP) to albumin (CAR) and the syndrome type of Wei-Qi-Ying-Xue in patients with severe coronavirus disease 2019 (COVID-19).Methods:A case-control study was conducted to select 63 severe patients with COVID-19 admitted to the Dongzhimen Hospital of Beijing University of Chinese Medicine from December 2022 to December 2023, including 50 severe cases and 13 critical cases. The clinical data of the patients were collected. According to the syndrome differentiation of Wei-Qi-Ying-Xue, there were 21 cases of Qi syndrome, 20 cases of Ying syndrome and 22 cases of Xue syndrome. The differences of CRP, ALB and CAR levels in patients with different Wei-Qi-Ying-Xue syndromes were compared. Spearman correlation test was used to test the correlation between CRP, ALB, CAR and the Wei-Qi-Ying-Xue syndrome type, and the receiver operating characteristic (ROC) curve was used to detect the diagnostic efficacy of CRP, ALB and CAR on the Wei-Qi-Ying-Xue syndrome type.Results:There was a statistically significant difference in the clinical classification of Western medicine among the three groups ( P<0.05). The CAR of the Ying group and the Xue group was higher than that of the Qi group ( P<0.05), while there was no statistically significant difference in age and comorbidities (all P>0.05). The CRP of the Xue group was higher than that of the Qi group ( P<0.05), and the ALB of the Ying group and the Xue group was lower than that of the Qi group (all P<0.05). Correlation analysis showed that there was a correlation between the Wei-Qi-Ying-Xue syndrome type and CRP, ALB and CAR ( P<0.05), among which CAR changed most significantly with the change of Wei-Qi-Ying-Xue syndrome type. ROC curve analysis showed that CRP, ALB and CAR had good diagnostic value for Qi syndrome and Xue syndrome ( P<0.05). The critical values of the diagnosis of Qi syndrome were 48.57 mg/L, 34.20 g/L and 2.97. The critical values of the diagnosis of Xue syndrome were 28.30 mg/L, 26.6 g/L and 5.96. Conclusions:CAR ratio is correlated with the Wei-Qi-Ying-Xue syndrome type of severe COVID-19 patients, and its level changes are in line with the evolution law of Wei-Qi-Ying-Xue syndrome. CAR≤2.97 is contributed to the diagnosis of Qi syndrome, and CAR>5.96 is contributed to the diagnosis of Xue syndrome. CAR may be an objective index related to the Wei-Qi-Ying-Xue syndrome type of severe COVID-19 patients.

Objective:To explore the relationship between changes in levels of thrombomodulin (TM) and non high-density lipoprotein cholesterol (non-HDL-C) with ascending aortic elastic function and degree of coronary artery disease (CHD) in patients with coronary heart disease (CHD).Methods:A total of 147 patients with coronary heart disease diagnosed through coronary angiography at Yulin First Hospital from January 2018 to December 2022 were selected as the CHD group. In addition, 90 volunteers who underwent health examinations at our hospital and did not experience coronary artery disease were selected as the control group. Two groups were compared in terms of blood lipids [triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C)], ascending aortic elastic function parameters [arterial dilation (AD), arterial stiffness index (ASI)], TM, non HDL-C levels, and other indicators, and stratified analysis was conducted according to the number of coronary lesions. The linear correlation analysis method was used to analyze the relationship between TM, non-HDL-C, Gensini score, and ascending aortic elastic function parameters.Results:The serum levels of TG, TC, LDL-C, TM, and non HDL-C in the CHD group were significantly higher than those in the control group, while the HDL-C levels were lower than those in the control group, with statistical significance (all P<0.05). The ASI of the ascending aorta in the CHD group was significantly higher than that in the control group, while the AD was lower than that in the control group, and the differences were statistically significant (all P<0.05). The serum levels of TG, TC, LDL-C, TM, and non HDL-C in CHD patients with multiple coronary artery lesions were significantly higher than those in patients with dual or single coronary artery lesions, and the HDL-C levels were lower than those in patients with dual or single coronary artery lesions, with statistical significance (all P<0.05); The serum levels of TM and non HDL-C in CHD patients with dual coronary artery disease were significantly higher than those in single coronary artery disease patients, and the HDL-C levels were lower than those in single coronary artery disease patients, with statistical significance (all P<0.05). The ASI of CHD patients with multiple coronary artery lesions was significantly higher than that of patients with dual or single coronary artery lesions, and the AD was lower than that of patients with dual or single coronary artery lesions, with statistical significance (all P<0.05); The ASI of CHD patients with dual coronary artery disease was significantly higher than that of patients with single coronary artery disease, and the AD was lower than that of patients with single coronary artery disease, with statistical significance (all P<0.05). The TM, non HDL-C levels in CHD patients were significantly negatively correlated with AD (all P<0.05), and positively correlated with ASI and Gensini scores (all P<0.05). Conclusions:The levels of TM and non HDL-C in CHD patients significantly increase, and the ascending aortic elasticity function was decreased. TM and non HDL-C are related to coronary elasticity function and the severity of coronary artery disease.